441 lines
14 KiB
C++
441 lines
14 KiB
C++
// © 2016 and later: Unicode, Inc. and others.
|
|
// License & terms of use: http://www.unicode.org/copyright.html
|
|
/*
|
|
*******************************************************************************
|
|
* Copyright (C) 2010-2011, International Business Machines
|
|
* Corporation and others. All Rights Reserved.
|
|
*******************************************************************************
|
|
* file name: bytestrie.cpp
|
|
* encoding: UTF-8
|
|
* tab size: 8 (not used)
|
|
* indentation:4
|
|
*
|
|
* created on: 2010sep25
|
|
* created by: Markus W. Scherer
|
|
*/
|
|
|
|
#include "unicode/utypes.h"
|
|
#include "unicode/bytestream.h"
|
|
#include "unicode/bytestrie.h"
|
|
#include "unicode/uobject.h"
|
|
#include "cmemory.h"
|
|
#include "uassert.h"
|
|
|
|
U_NAMESPACE_BEGIN
|
|
|
|
BytesTrie::~BytesTrie() {
|
|
uprv_free(ownedArray_);
|
|
}
|
|
|
|
// lead byte already shifted right by 1.
|
|
int32_t
|
|
BytesTrie::readValue(const uint8_t *pos, int32_t leadByte) {
|
|
int32_t value;
|
|
if(leadByte<kMinTwoByteValueLead) {
|
|
value=leadByte-kMinOneByteValueLead;
|
|
} else if(leadByte<kMinThreeByteValueLead) {
|
|
value=((leadByte-kMinTwoByteValueLead)<<8)|*pos;
|
|
} else if(leadByte<kFourByteValueLead) {
|
|
value=((leadByte-kMinThreeByteValueLead)<<16)|(pos[0]<<8)|pos[1];
|
|
} else if(leadByte==kFourByteValueLead) {
|
|
value=(pos[0]<<16)|(pos[1]<<8)|pos[2];
|
|
} else {
|
|
value=(pos[0]<<24)|(pos[1]<<16)|(pos[2]<<8)|pos[3];
|
|
}
|
|
return value;
|
|
}
|
|
|
|
const uint8_t *
|
|
BytesTrie::jumpByDelta(const uint8_t *pos) {
|
|
int32_t delta=*pos++;
|
|
if(delta<kMinTwoByteDeltaLead) {
|
|
// nothing to do
|
|
} else if(delta<kMinThreeByteDeltaLead) {
|
|
delta=((delta-kMinTwoByteDeltaLead)<<8)|*pos++;
|
|
} else if(delta<kFourByteDeltaLead) {
|
|
delta=((delta-kMinThreeByteDeltaLead)<<16)|(pos[0]<<8)|pos[1];
|
|
pos+=2;
|
|
} else if(delta==kFourByteDeltaLead) {
|
|
delta=(pos[0]<<16)|(pos[1]<<8)|pos[2];
|
|
pos+=3;
|
|
} else {
|
|
delta=(pos[0]<<24)|(pos[1]<<16)|(pos[2]<<8)|pos[3];
|
|
pos+=4;
|
|
}
|
|
return pos+delta;
|
|
}
|
|
|
|
UStringTrieResult
|
|
BytesTrie::current() const {
|
|
const uint8_t *pos=pos_;
|
|
if(pos==NULL) {
|
|
return USTRINGTRIE_NO_MATCH;
|
|
} else {
|
|
int32_t node;
|
|
return (remainingMatchLength_<0 && (node=*pos)>=kMinValueLead) ?
|
|
valueResult(node) : USTRINGTRIE_NO_VALUE;
|
|
}
|
|
}
|
|
|
|
UStringTrieResult
|
|
BytesTrie::branchNext(const uint8_t *pos, int32_t length, int32_t inByte) {
|
|
// Branch according to the current byte.
|
|
if(length==0) {
|
|
length=*pos++;
|
|
}
|
|
++length;
|
|
// The length of the branch is the number of bytes to select from.
|
|
// The data structure encodes a binary search.
|
|
while(length>kMaxBranchLinearSubNodeLength) {
|
|
if(inByte<*pos++) {
|
|
length>>=1;
|
|
pos=jumpByDelta(pos);
|
|
} else {
|
|
length=length-(length>>1);
|
|
pos=skipDelta(pos);
|
|
}
|
|
}
|
|
// Drop down to linear search for the last few bytes.
|
|
// length>=2 because the loop body above sees length>kMaxBranchLinearSubNodeLength>=3
|
|
// and divides length by 2.
|
|
do {
|
|
if(inByte==*pos++) {
|
|
UStringTrieResult result;
|
|
int32_t node=*pos;
|
|
U_ASSERT(node>=kMinValueLead);
|
|
if(node&kValueIsFinal) {
|
|
// Leave the final value for getValue() to read.
|
|
result=USTRINGTRIE_FINAL_VALUE;
|
|
} else {
|
|
// Use the non-final value as the jump delta.
|
|
++pos;
|
|
// int32_t delta=readValue(pos, node>>1);
|
|
node>>=1;
|
|
int32_t delta;
|
|
if(node<kMinTwoByteValueLead) {
|
|
delta=node-kMinOneByteValueLead;
|
|
} else if(node<kMinThreeByteValueLead) {
|
|
delta=((node-kMinTwoByteValueLead)<<8)|*pos++;
|
|
} else if(node<kFourByteValueLead) {
|
|
delta=((node-kMinThreeByteValueLead)<<16)|(pos[0]<<8)|pos[1];
|
|
pos+=2;
|
|
} else if(node==kFourByteValueLead) {
|
|
delta=(pos[0]<<16)|(pos[1]<<8)|pos[2];
|
|
pos+=3;
|
|
} else {
|
|
delta=(pos[0]<<24)|(pos[1]<<16)|(pos[2]<<8)|pos[3];
|
|
pos+=4;
|
|
}
|
|
// end readValue()
|
|
pos+=delta;
|
|
node=*pos;
|
|
result= node>=kMinValueLead ? valueResult(node) : USTRINGTRIE_NO_VALUE;
|
|
}
|
|
pos_=pos;
|
|
return result;
|
|
}
|
|
--length;
|
|
pos=skipValue(pos);
|
|
} while(length>1);
|
|
if(inByte==*pos++) {
|
|
pos_=pos;
|
|
int32_t node=*pos;
|
|
return node>=kMinValueLead ? valueResult(node) : USTRINGTRIE_NO_VALUE;
|
|
} else {
|
|
stop();
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
}
|
|
|
|
UStringTrieResult
|
|
BytesTrie::nextImpl(const uint8_t *pos, int32_t inByte) {
|
|
for(;;) {
|
|
int32_t node=*pos++;
|
|
if(node<kMinLinearMatch) {
|
|
return branchNext(pos, node, inByte);
|
|
} else if(node<kMinValueLead) {
|
|
// Match the first of length+1 bytes.
|
|
int32_t length=node-kMinLinearMatch; // Actual match length minus 1.
|
|
if(inByte==*pos++) {
|
|
remainingMatchLength_=--length;
|
|
pos_=pos;
|
|
return (length<0 && (node=*pos)>=kMinValueLead) ?
|
|
valueResult(node) : USTRINGTRIE_NO_VALUE;
|
|
} else {
|
|
// No match.
|
|
break;
|
|
}
|
|
} else if(node&kValueIsFinal) {
|
|
// No further matching bytes.
|
|
break;
|
|
} else {
|
|
// Skip intermediate value.
|
|
pos=skipValue(pos, node);
|
|
// The next node must not also be a value node.
|
|
U_ASSERT(*pos<kMinValueLead);
|
|
}
|
|
}
|
|
stop();
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
|
|
UStringTrieResult
|
|
BytesTrie::next(int32_t inByte) {
|
|
const uint8_t *pos=pos_;
|
|
if(pos==NULL) {
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
if(inByte<0) {
|
|
inByte+=0x100;
|
|
}
|
|
int32_t length=remainingMatchLength_; // Actual remaining match length minus 1.
|
|
if(length>=0) {
|
|
// Remaining part of a linear-match node.
|
|
if(inByte==*pos++) {
|
|
remainingMatchLength_=--length;
|
|
pos_=pos;
|
|
int32_t node;
|
|
return (length<0 && (node=*pos)>=kMinValueLead) ?
|
|
valueResult(node) : USTRINGTRIE_NO_VALUE;
|
|
} else {
|
|
stop();
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
}
|
|
return nextImpl(pos, inByte);
|
|
}
|
|
|
|
UStringTrieResult
|
|
BytesTrie::next(const char *s, int32_t sLength) {
|
|
if(sLength<0 ? *s==0 : sLength==0) {
|
|
// Empty input.
|
|
return current();
|
|
}
|
|
const uint8_t *pos=pos_;
|
|
if(pos==NULL) {
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
int32_t length=remainingMatchLength_; // Actual remaining match length minus 1.
|
|
for(;;) {
|
|
// Fetch the next input byte, if there is one.
|
|
// Continue a linear-match node without rechecking sLength<0.
|
|
int32_t inByte;
|
|
if(sLength<0) {
|
|
for(;;) {
|
|
if((inByte=*s++)==0) {
|
|
remainingMatchLength_=length;
|
|
pos_=pos;
|
|
int32_t node;
|
|
return (length<0 && (node=*pos)>=kMinValueLead) ?
|
|
valueResult(node) : USTRINGTRIE_NO_VALUE;
|
|
}
|
|
if(length<0) {
|
|
remainingMatchLength_=length;
|
|
break;
|
|
}
|
|
if(inByte!=*pos) {
|
|
stop();
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
++pos;
|
|
--length;
|
|
}
|
|
} else {
|
|
for(;;) {
|
|
if(sLength==0) {
|
|
remainingMatchLength_=length;
|
|
pos_=pos;
|
|
int32_t node;
|
|
return (length<0 && (node=*pos)>=kMinValueLead) ?
|
|
valueResult(node) : USTRINGTRIE_NO_VALUE;
|
|
}
|
|
inByte=*s++;
|
|
--sLength;
|
|
if(length<0) {
|
|
remainingMatchLength_=length;
|
|
break;
|
|
}
|
|
if(inByte!=*pos) {
|
|
stop();
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
++pos;
|
|
--length;
|
|
}
|
|
}
|
|
for(;;) {
|
|
int32_t node=*pos++;
|
|
if(node<kMinLinearMatch) {
|
|
UStringTrieResult result=branchNext(pos, node, inByte);
|
|
if(result==USTRINGTRIE_NO_MATCH) {
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
// Fetch the next input byte, if there is one.
|
|
if(sLength<0) {
|
|
if((inByte=*s++)==0) {
|
|
return result;
|
|
}
|
|
} else {
|
|
if(sLength==0) {
|
|
return result;
|
|
}
|
|
inByte=*s++;
|
|
--sLength;
|
|
}
|
|
if(result==USTRINGTRIE_FINAL_VALUE) {
|
|
// No further matching bytes.
|
|
stop();
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
pos=pos_; // branchNext() advanced pos and wrote it to pos_ .
|
|
} else if(node<kMinValueLead) {
|
|
// Match length+1 bytes.
|
|
length=node-kMinLinearMatch; // Actual match length minus 1.
|
|
if(inByte!=*pos) {
|
|
stop();
|
|
return USTRINGTRIE_NO_MATCH;
|
|
}
|
|
++pos;
|
|
--length;
|
|
break;
|
|
} else if(node&kValueIsFinal) {
|
|
// No further matching bytes.
|
|
stop();
|
|
return USTRINGTRIE_NO_MATCH;
|
|
} else {
|
|
// Skip intermediate value.
|
|
pos=skipValue(pos, node);
|
|
// The next node must not also be a value node.
|
|
U_ASSERT(*pos<kMinValueLead);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
const uint8_t *
|
|
BytesTrie::findUniqueValueFromBranch(const uint8_t *pos, int32_t length,
|
|
UBool haveUniqueValue, int32_t &uniqueValue) {
|
|
while(length>kMaxBranchLinearSubNodeLength) {
|
|
++pos; // ignore the comparison byte
|
|
if(NULL==findUniqueValueFromBranch(jumpByDelta(pos), length>>1, haveUniqueValue, uniqueValue)) {
|
|
return NULL;
|
|
}
|
|
length=length-(length>>1);
|
|
pos=skipDelta(pos);
|
|
}
|
|
do {
|
|
++pos; // ignore a comparison byte
|
|
// handle its value
|
|
int32_t node=*pos++;
|
|
UBool isFinal=(UBool)(node&kValueIsFinal);
|
|
int32_t value=readValue(pos, node>>1);
|
|
pos=skipValue(pos, node);
|
|
if(isFinal) {
|
|
if(haveUniqueValue) {
|
|
if(value!=uniqueValue) {
|
|
return NULL;
|
|
}
|
|
} else {
|
|
uniqueValue=value;
|
|
haveUniqueValue=TRUE;
|
|
}
|
|
} else {
|
|
if(!findUniqueValue(pos+value, haveUniqueValue, uniqueValue)) {
|
|
return NULL;
|
|
}
|
|
haveUniqueValue=TRUE;
|
|
}
|
|
} while(--length>1);
|
|
return pos+1; // ignore the last comparison byte
|
|
}
|
|
|
|
UBool
|
|
BytesTrie::findUniqueValue(const uint8_t *pos, UBool haveUniqueValue, int32_t &uniqueValue) {
|
|
for(;;) {
|
|
int32_t node=*pos++;
|
|
if(node<kMinLinearMatch) {
|
|
if(node==0) {
|
|
node=*pos++;
|
|
}
|
|
pos=findUniqueValueFromBranch(pos, node+1, haveUniqueValue, uniqueValue);
|
|
if(pos==NULL) {
|
|
return FALSE;
|
|
}
|
|
haveUniqueValue=TRUE;
|
|
} else if(node<kMinValueLead) {
|
|
// linear-match node
|
|
pos+=node-kMinLinearMatch+1; // Ignore the match bytes.
|
|
} else {
|
|
UBool isFinal=(UBool)(node&kValueIsFinal);
|
|
int32_t value=readValue(pos, node>>1);
|
|
if(haveUniqueValue) {
|
|
if(value!=uniqueValue) {
|
|
return FALSE;
|
|
}
|
|
} else {
|
|
uniqueValue=value;
|
|
haveUniqueValue=TRUE;
|
|
}
|
|
if(isFinal) {
|
|
return TRUE;
|
|
}
|
|
pos=skipValue(pos, node);
|
|
}
|
|
}
|
|
}
|
|
|
|
int32_t
|
|
BytesTrie::getNextBytes(ByteSink &out) const {
|
|
const uint8_t *pos=pos_;
|
|
if(pos==NULL) {
|
|
return 0;
|
|
}
|
|
if(remainingMatchLength_>=0) {
|
|
append(out, *pos); // Next byte of a pending linear-match node.
|
|
return 1;
|
|
}
|
|
int32_t node=*pos++;
|
|
if(node>=kMinValueLead) {
|
|
if(node&kValueIsFinal) {
|
|
return 0;
|
|
} else {
|
|
pos=skipValue(pos, node);
|
|
node=*pos++;
|
|
U_ASSERT(node<kMinValueLead);
|
|
}
|
|
}
|
|
if(node<kMinLinearMatch) {
|
|
if(node==0) {
|
|
node=*pos++;
|
|
}
|
|
getNextBranchBytes(pos, ++node, out);
|
|
return node;
|
|
} else {
|
|
// First byte of the linear-match node.
|
|
append(out, *pos);
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
void
|
|
BytesTrie::getNextBranchBytes(const uint8_t *pos, int32_t length, ByteSink &out) {
|
|
while(length>kMaxBranchLinearSubNodeLength) {
|
|
++pos; // ignore the comparison byte
|
|
getNextBranchBytes(jumpByDelta(pos), length>>1, out);
|
|
length=length-(length>>1);
|
|
pos=skipDelta(pos);
|
|
}
|
|
do {
|
|
append(out, *pos++);
|
|
pos=skipValue(pos);
|
|
} while(--length>1);
|
|
append(out, *pos);
|
|
}
|
|
|
|
void
|
|
BytesTrie::append(ByteSink &out, int c) {
|
|
char ch=(char)c;
|
|
out.Append(&ch, 1);
|
|
}
|
|
|
|
U_NAMESPACE_END
|